Does homosexuality make evolutionary sense?

This is something I've been pondering myself recently, the leading scientific opinion is that jomosexuality is based on biology rather than being a choice, but I still wonder. I think Nature vs Nuture comes into play. Just wondering what others thoughts are.

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Your links are from a religious anti-gay web site with a vested interest in "proving" it is a choice so that they can condemn the "lifestyle". Have a look at John's link http://www.eurekalert.org/pub_releases/2004-03/ohs-bbh030804.php about gay sheep. Seems rather hard to claim that is a social construct. Also, it seems unlikely that there is a single "gay gene". Since sexual orientation is a spectrum, it seems likely that there are several factors it multiple causative pathways. Here are some more links showing physiological differences in homosexual and transsexual brains:

I have provided you with an enormous amount of material. As a Ph.D. physicist, I know good research when I see it. Studies using home movies of "pre-gay" children, for example, have shown characteristics controlled by some of the gender-dimorphic brain areas, and the children as they were then had not indulged in any sexual behaviour. Other studies have also tended to discredit the theory that behaviour causes the brain changes that coincide with being trans or gay. I simply don't have the time to rebut all your points. You need to read more and see where the weight of evidence lies.

You appear to be, and indeed state that you are starting from your own viewpoint that homosexuality and transgender conditions are social constructs, and have said that you will stick to that until you can do your own research. I can only conclude that nothing is going to cause you to so much as doubt the correctness of your position.

There is also the issue of nurture becoming nature. David Buss' work is on this subject with sexual attraction. Gender might have been more nurture at one time, but natural selection over the process of human evolution would have likely transformed it into something more biological, whereas the original could have simply been traits and strong tendencies.

Just tried every single link. All work except one "Sexual differentiation of the human brain in relation to gender ide..." which seems to have been taken off that server. They are just links I have collected from various article, or via web searches, and put in a folder in my bookmarks. I just put them out there for you. I see the trend of the research I have read as being strongly suggestive of a genetic component to being LGBT. You don't. As more reasearch becomes available, I may or may not change my view, or maybe you will. Or we both might be wrong.

A gene for homosexuality will have the same evolutionary advantages/disadvantages as one for celibacy or infertility. Unless anyone is also looking for genetic explanations for some choosing to stay away from sex and some unable to conceive/make pregnant, not sure why they would want to look for genetic explanations fo homosexuality.

The "Sneaky mate" theory is so ridiculous since it doesn't even explain true homosexuality but only bisexuals pretending to be homosexual as a strategy, not sure why anyone would want to even mention it.

So from an evolutionary standpoint the existence of homosexuality is not much different from the existence of celibacy or infertility.

Among the non-genetic explanations the theory that effeminate men become homosexuals and masculine women lesbians looks promising until you consider who their partners would be. If an effiminate man prefers a man because he himself feels feminine, why would his partner, who would be masculine, prefer a feminine man rather than a feminine woman? Why would two effeminate men or masculine women be attracted to each other? One possible explanation is that, while they may each prefer a person of their desired gender who expresses stronger tendencies of that gender, they settle for the one among those available, someone who is much like themselves.

All that is , of course, assuming the cause is biological. If it is not and it is a choice they are making, much like some choose to be celibate, for whatever reasons and yet others choose to remain childless, again for whatever reasons, searching for biological causes to explain such behaviours is not of much significance.

So from an evolutionary standpoint the existence of homosexuality is not much different from the existence of celibacy or infertility.

This opinion assumes that the desire to reproduce is not separate from sexual preference. Just as couples with difficulty conceiving may have gone outside the relationship to try to produce desired children before things like IVF, I'm sure people with homosexual preferences would have done the same if they desired children. And plenty of people today don't accept their homosexual preference until they've spent a bit of time trying to convince themselves they are heterosexual for a variety of reasons. My uncle was married for years and had 3 children before he came out of the closet. One of his sons is gay and we all knew he was from a very early age. We also knew my uncle was gay long before he admitted it to himself. This is a very obvious example of how a "gay gene" carried solely by homosexuals would not die out due to natural selection.

So people with homosexual preferences who are in heterosexual partnerships or those who come out later in life are not a new thing. And if there are biological aspects to homosexuality which are not solely carried by homosexuals (perhaps a by product of high fertility females, for example) it obviously would not have died out either.

I do agree that searching for biological causes to explain such behaviors is not of much significance. I still find it interesting.

From an evolutionary standpoint the only significant things are those that affect the survival of the genes across generations. If the presence of a gene decreases the likelihood of the carrier having offspring, such a gene will eventually be selected out. A preference for seeking mates of the same gender reduces the likelihood of the person reproducing and passing on the genes. The effect is the same when the person chooses celibacy or is infertile. If there are specific genes causing anyone of them they all have the same chances of being represented in successive generations, which is nil.

Menopause makes women infertile. Genes that cause death or infertility at a late stage still may not be selected out because they are already repesented in a youger generation and may even be beneficial to the genes by removing the older carriers from competition for resources in case of death and by allowing the older carriers to spend more time and resources on the well-being of youger carriers thus increasing the chances of the younger carriers.

The person you referred to is no more genetically gay than a woman who bore 3 children and reached menopause being termed infertile. On the otherhand if that is the only "homosexuality" we are talking about, a loss of interest in procreative sex and possibly interest in exclusively recreative sex after a certain age/stage, there might indeed by a gene for it, much like one for causing menopause in women. In fact, that is the best argument possible for those who insist on the existence of a 'gay gene', that it is a gene that becomes active late in life and thus ecapes evolutionary filtering just like genes for senility etc and all the instances of early age gay behaviour are simply the gene becoming active early!

Of course, a simpler non-genetic, non-biological explanation would be that after a certain age the male loses interest in paying the cost associated with procreative sex and looks for cheaper recreative sex options and in some the wisdom may be acquired very early in life :-)

If the presence of a gene decreases the likelihood of the carrier having offspring, such a gene will eventually be selected out.

Once again, you're assuming people with homosexual preference are as likely to have offspring as celibate or infertile people. This is a completely false assumption. I could name half a dozen married closeted gay acquaintances right now so I'm sure this isn't a "new thing." And many openly gay people have or desire children so your "loss of interest in procreative sex" theory is absurd. You also didn't address the possibility of a biological aspect passed down not through homosexuals, but perhaps maternally.

I don't particularly care either way, but studies do seem to indicate a biological component to homosexuality. However, it's obvious that you wantto believe homosexuality is completely a choice. If that's the case, carry on.

I am always amused by this genetically inherited homsexual "preference" concept. How about genetically inherited "preference" for celibacy, "likely" infertility and a "preference" for masturbation? Anyone looking into those possibilities as well? All of them can be "inherited" in the same way as the "gay gene".

Being interested in children and being interested in a particular way of achieving that objective (procreative sex) are entirely different things. One can be interested in one and not the other.

I care a rat's behind what an adult does with his/her body or how a group (two or more) of consenting adults entertain themselves. That's their business, not mine. But I do care about the standards of evidence and argument in discussions termed as scientific and when they are diluted to suit political agendas, I am concerned, because scientific discourse is everybody's business.

Yes, in the absence of overwhelming evidence, I believe all "preferences" that do not manifest in a significant percentage of the populations within the species across times and geographies to be just that, preferences, influenced by the circumstances rather than biology or genetics as should any person who claims to be rational. If a particular preference is suspected, for scientific reasons, to be of biological/genetic origin rather than social/psychological/cultural or circumstantial origin, so should every similar preference/condition that would have the same biological/genetic consequences, If even the possibility that one such preference/condition is genetic/biological in origin sounds absurd so should the entire class of preferences/conditions.

To me the possibility of genetically inherited/biologically determined preference for celibacy sounds absurd. It is in the exact same class as a genetically inherited/biologically conditioned preference for homosexuality. Of course, sounding absurd doesn't mean it is not possible. However, if one is possible so is the other. Regardless of how many "studies" say it, I will believe the claims for one only when similar claims are established for the other.

I used the word preference because you kept implying that homosexuals would not reproduce. Though a male might prefer other males, society or the desire to reproduce often finds these males in heterosexual relationships, at least for a period of time.

And celibacy chosen due to lifelong lack of sex drive or excessive masturbation due to incredibly high sex drive can certainly be biologically driven.